3 Theories About How Fantastic Four Will Connect to Avengers: Doomsday

Marvel Studios recently dropped a bombshell by revealing the full cast lineup for the upcoming Avengers: Doomsday, confirming that all four members of Marvel’s First Family will appear alongside Earth’s Mightiest Heroes. While The Fantastic Four: First Steps hasn’t even hit theaters yet, we already know it won’t be the last time we see Pedro Pascal’s Reed Richards, Vanessa Kirby’s Sue Storm, Joseph Quinn’s Johnny Storm, and Ebon Moss-Bachrach’s Ben Grimm. This creates a fascinating puzzle for MCU fans to solve: how exactly will the Fantastic Four cross paths with the Avengers? The situation is particularly intriguing because Marvel has already confirmed that The Fantastic Four: First Steps movie takes place in a 1960s-inspired, retro-futuristic setting — clearly separate from the main MCU Sacred Timeline where the Avengers exist. 

With Galactus (Ralph Ineson) and Silver Surfer (Julia Garner) established as the primary threats in First Steps, something significant must occur to bridge these separate realities and bring the Fantastic Four into the multiversal chaos building toward Avengers: Doomsday and its sequel, Secret Wars. This aligns with Marvel Studios’ approach to building the Multiverse Saga, where boundaries between different realities have become increasingly permeable. With the Russo brothers drawing inspiration from both the original 1984 “Secret Wars” storyline and Jonathan Hickman’s 2015 reimagining, which heavily featured incursion events where universes collide, we can expect a cosmic-scale explanation for the Fantastic Four’s eventual arrival in the main MCU timeline. Here are three compelling theories about how Marvel Studios might connect the retro world of the Fantastic Four with Avengers: Doomsday:

The Fantastic Four’s Earth Is Destroyed

In The Fantastic Four: First Steps, Marvel’s First Family faces the Devourer of Worlds as he attempts to “devour the entire planet and everyone on it,” according to the official synopsis. While superhero films typically end with the heroes triumphing, the multiverse framework provides Marvel with the perfect opportunity to subvert expectations. As such, the most dramatic scenario would see the Fantastic Four failing to stop Galactus from consuming their Earth, forcing them to escape their doomed timeline. Imagine a devastating third-act twist where the Fantastic Four cannot prevent their world’s destruction despite their best efforts and personal sacrifices. With Reed Richards’ genius-level intellect, he might develop interdimensional travel technology that allows his family to escape into the multiverse just as Galactus consumes their Earth.

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Alternatively, even if they succeed in repelling Galactus, their victory could be short-lived. The cosmic chaos resulting from the battle might trigger an incursion event — the catastrophic collision of universes that Doctor Strange warned about in Multiverse of Madness. Reed might detect the impending disaster and realize their universe is doomed regardless of their victory over Galactus. This scenario would provide emotional weight to their introduction into the main MCU timeline, positioning them as refugees with firsthand knowledge of the multiverse-level threats facing all realities. Their expertise would make them valuable allies to the Avengers while giving them a personal stake in preventing similar catastrophes in their new home.

The Fantastic Four Is Hunting Doctor Doom

One of the most exciting announcements for Avengers: Doomsday was Robert Downey Jr.’s return to the MCU as Victor Von Doom, who’ll be the primary antagonist in the upcoming crossover movies. Given Doom’s established history as the Fantastic Four’s nemesis, it would make narrative sense for the team to arrive in the Sacred Timeline in pursuit of him. Perhaps in The Fantastic Four: First Steps epilogue or a post-credits scene, we’ll discover that Doom has been monitoring the battle with Galactus from the shadows, using the cosmic disturbance as cover to escape into the multiverse. Or maybe he had been previously imprisoned by the Fantastic Four, and Galactus’ arrival gives him the perfect opportunity to escape.

The pursuit of Doom provides a narrative thread that would seamlessly integrate the Fantastic Four into the events of Avengers: Doomsday. Reed Richards, having traced Doom’s interdimensional signature to the main MCU timeline, would lead his family on a desperate chase to prevent Doom from wreaking havoc across a new universe. When they arrive, they might initially clash with the Avengers due to misunderstandings or cultural differences before allying against their common enemy. This approach would honor the classic comic book rivalry between Reed and Doom while establishing high personal stakes for the Fantastic Four’s involvement in the larger multiversal conflict.

The Fantastic Four Is Summoned By The Beyonder

Following the original “Secret Wars” storyline in Marvel Comics, the Beyonder might summon different superpowered people to battle for his amusement. Or maybe the Beyonder is aware of the incursions happening in the MCU’s multiverse and is trying to decide whose reality is worth saving. That could pitch the Fantastic Four against the X-Men and the Sacred Timeline heroes before everyone joins forces to face the threat of Doom, who’s using the Beyonder’s challenge as an opportunity to take control of the Multiverse.

The Secret Wars comic storyline provides Marvel Studios with a ready-made framework to justify gathering heroes from across the multiverse. This approach would honor the source material while creating the high-stakes crossover event that fans expect from an Avengers film. The initial conflicts between heroes from different realities would showcase their unique perspectives before they unite against a greater threat, exactly the kind of storytelling that made the original “Secret Wars” such a compelling event in Marvel Comics.

The Fantastic Four: First Steps arrives in theaters on July 25th, while Avengers: Doomsday is scheduled to be released on May 1, 2026.

How do you think The Fantastic Four: First Steps will connect to Avengers: Doomsday? Share your theories in the comments!